That's pretty scary to me and Disney probably "sees" that too and will want to continue to profit from that.
If Disney see that people are willing to pay extra (a lot extra) for a night of "low capacity" just to go on rides with short lines (and could care less about the special stuff), I definitely see them continuing to raise
ticket prices or having "parties" all year long (which essentially are "paid" EMH).
Come on .. how many would pay extra for a "Indepencence party" a few times a week in July so you could have a 1/4 capacity filled park all night during the peak summer hours? They probably wouldn't even need to do anything special .. some may simply be willing to pay for guaranteed reduced capacity.